The invention relates to a method of conveying a stream of printed products in which, in a first section of an endlessly-circulating, first conveyor loop, the printed products are disposed individually one behind the other and oriented essentially tangentially to the conveying direction, and are transferred to a second endlessly-circulating conveyor loop. The invention further relates to an apparatus that can be used to execute such methods.
Methods of the above-described type are used, for example, to convey printed products that have been processed with a cutting apparatus. The cutting apparatus removes excess lateral edges of stapled, bound or unbound or unstapled printed products that have been assembled or collated. To this end, the printed products are usually supplied to the cutting apparatus along a fixed path of movement in a position oriented tangentially to their conveying direction, that is, in a position in which the planes of the individual sheets of the printed products extend parallel to the conveying direction; the printed products are then conveyed through the cutting apparatus and exit it. The printed products are subsequently taken up by a first conveying device circulating along a first conveyor loop, which usually maintains their orientation, and are transferred to a second conveying device that circulates along a second conveyor loop in order to be conveyed to a device, a so-called stacker, that forms bundles of printed products that are ready to be shipped.
The second conveying device typically has a plurality of grippers that pass a diversion point of the first conveyor loop along the second conveyor loop and serve to convey respectively one of the processed printed products. To take up the printed products conveyed along the first conveyor loop, the grippers are opened in the region of the diversion point and closed after taking a printed product at a transfer point in the region of the diversion point for transporting the printed products further along the second conveyor loop. The transfer is effected by the insertion of the processed printed products into the grippers opened at the transfer point.
To assure reliable operation of an apparatus for executing such methods, the grippers must pass the diversion point of the first conveyor loop along the second conveyor loop at precisely fixed intervals. It is also necessary for the circulating speed of the grippers and the conveying speed for the printed products conveyed along the first conveyor loop to be identical. The operating speed of such apparatuses is limited by the time to be made available for inserting the individual printed products at the transfer point.